Specialist cleaning for Victorian and Georgian brickwork. London stock brick is softer than modern brick, acid-vulnerable, and routinely damaged by contractors who don't know its properties.
London's Victorian and Georgian terraces are built predominantly from London stock — a yellow-grey brick produced from Thames valley brick-earth mixed with ash and chalk. It's the material that defines the palette of inner London. It's also significantly softer than modern machine-made brick, and its behaviour under cleaning is completely different.
Hydrochloric acid, routinely used to clean modern brickwork, will dissolve the face of London stock. High-pressure water washing erodes the pointing and saturates the masonry. Even aggressive scrubbing can abrade the softer stock face in ways that aren't immediately visible but become obvious years later as the surface weathers unevenly.
We've been called in to assess buildings after contractors have used inappropriate methods. The damage — acid-etched faces, eroded arises, blown pointing — is permanent.
DOFF steam cleaning is our primary method for London stock brick. The superheated steam at low pressure lifts biological growth, atmospheric soiling, and carbon deposits without abrading the brick face or introducing significant water into the wall. It's appropriate for most Victorian and Georgian stock brick facades.
TORC cleaning may be specified for robust Victorian red brick with heavy carbonated soiling — not for London stock. The aggregate component in TORC would damage soft stock brick. When TORC is used on brick at all, it's on hard engineering brick or Victorian terracotta, with care.
Chemical poultice is appropriate for localised staining — iron staining, salt efflorescence, lime runs from joint work. Applied to the affected area, left to draw the stain out of the brick, then carefully removed. No mechanical action on the substrate.
London stock brick accounts for most pre-1900 residential and commercial construction in inner London. Yellow-grey, soft, lime-mortared. Requires careful method selection.
Victorian red brick — the harder, machine-pressed red brick used from the 1870s onwards on commercial buildings, schools, and higher-end residential. More tolerant of cleaning than stock, but still requires assessment.
Engineering brick — the very hard, dense, low-porosity brick used for arches, basements, and structural elements. Tolerates more robust methods.
Terracotta and Faience — the decorative ceramic cladding used extensively on late Victorian commercial buildings. Chemically distinct from brick; cleaning requires specialist approach.
We carry out free site surveys across London. We'll identify the brick type, assess the mortar condition, and look at the soiling closely before specifying anything. This matters more for brick than almost any other material — the wrong method on the wrong brick leaves damage that can't be undone.
Victorian London stock brick requires low-pressure methods — DOFF steam cleaning or controlled chemical systems specified for soft brick. No acid, no high-pressure water. We assess the brick condition and the soiling type on site before specifying anything.
No. Hydrochloric acid, commonly used on modern brick, will strip the face of London stock. The brick's softer composition and lime mortar joints make it highly vulnerable to acid damage. We've been called in after contractors have used acid on London stock — the damage is irreversible.
For Victorian and Georgian brickwork, DOFF superheated steam is typically the safest starting point. For heavier soiling, TORC may be appropriate on robust brick. The right answer depends on the brick type, age, and soiling — which is why we survey before specifying.
Not on period brick. High-pressure washing erodes the pointing, saturates the masonry, and damages the face of soft bricks. On modern brick in good condition it's sometimes acceptable. On Victorian or Georgian brickwork, it causes harm that takes years to become fully visible.